Ten thousand standard years ago, in the immediate aftermath of the Horus Heresy, Roboute Guilliman, the Primarch of the Ultramarines Legion, decreed that his XIII Legion would stand ready to oppose the Traitors who had fled into the Eye of Terror should they ever return to plague the Imperium. The Ultramarines had taken no part in the Battle of Terra, as they had been bogged down fighting aganst the Word Bearers Traitor Legion half a galaxy away. But Guilliman was determined that his Legion would never again find itself unable to respond to the more pressing threat. The solution was to ensure a continuous Ultramarines presence in the vicinity of the Eye of Terror, by maintaining an honour guard within the region made up of individual squads from different companies. In time, after the Seco